The design of suitable systems for moving articles from point A to point B, such as in an assembly line environment, is particularly important in the provision of industrial facilities for manufacturing or processing goods of various kinds. In many cases, these facilities require high production capacity, and these movement systems must be completely automated, highly efficient, and reliable, because any malfunction may halt the entire production. Naturally, the assembly of more complicated articles requires a longer or more complicated assembly line.
Due to limitations such as manufacturing plant size, the assembly line is often forced to follow a curved path around the interior of a building. At high speeds an assembly line may encounter a problem as it rounds a curve. A conveyor belt on the surface of an assembly line, upon which an article may be placed, may become uneven, as forces such as for example centrifugal forces, act on the surface of the conveyor belt and cause a portion of the conveyor belt to raise up from its support structure. The same problem may also occur over linear portions of an assembly line. For example a single edge, such as the inner edge or outer edge of the conveyor belt may lift from the surface of the assembly line so that the entire conveyor belt is no longer flush or level with the surface of the assembly line. In other words, a problem exists where the conveyor belt no longer lies flat on the assembly line as it rounds a corner at high speed, or as slack develops along a linear portion. This raising of the conveyor belt may for example cause a jamming of the assembly line, or may cause the items on the assembly line to fall off the conveyor belt or to shift into an unacceptable position, resulting in a shutting down of the assembly line, and costly repairs, or a delay in the items reaching their end destination. It also prevents the assembly line from operating at an increased speed.
Certain conveyor belts may be may be divided into sections in order to round corners. An example of this would be the conveyor belt at baggage claim terminal at an airport. In other instances, a barrier may be placed along the conveyor belt on the outer edge of the curve to prevent the items from flying off the conveyor belt. However, neither of these situations solves the aforementioned tilting or lifting of the conveyor belt in a high speed manufacturing line environment, both may result in damaging the items or the barrier itself, and neither does anything to prevent the items from shifting as a result of the tilt. The result is increased maintenance cost and reduced performance of the assembly line.
Another known situation involves using magnetic force in an effort to hold the conveyor belt to the assembly line where at least the assembly line and conveyor belt are made of a magnetic material. However, this situation requires that the conveyor belt be made of costly and heavy magnetic material and requires an inefficient lubrication system to ensure regular and smooth operation. Further, such a system may not be used if it is necessary to convey items that may be damaged by contact with metallic surfaces, and the magnets involved must be arranged so that their respective magnetic poles are oppositely orientated, thus increasing the chances of installation error, making it difficult to perform assembly and maintenance, and accordingly increasing the overall production and management costs of the conveyor belt.
Plastic assembly lines still have the shortcoming of oppositely oriented magnetic poles on adjacent magnets, and, importantly, since the attraction force is applied to the center or other single point of the conveyor belt, a level conveyor belt surface around a corner is still not ensured, since the lateral ends, (e.g., edges) of the loading surface still lift from the assembly line when proceeding through a curve at speed, even with the center or the conveyor belt subject to a magnetic field.